• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.490-497
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• 2020

This work has been initiated to find possibility whether recycled fine aggregate can be used as a source of aggregate for structural concrete or not. Two-stage mixing approach was chosen in order to maximize strength potential from recycled fine aggregate. Moisture content of the recycled fine aggregate was changed, and two different types of two-stage mixing approaches were applied to produce cement mortar. The strength of mortar made of 100% recycled fine aggregate by two-stage mixing approaches was compared to that of mortar made of 100% washed sea sand. According to the results, the effect of moisture content on compressive strength was observed from low water cement mortar(W/C 0.3). In case of W/C 0.5 cement mortar, no clear relationship was observed between moisture content and strength development. It was found that two-stage mixing approach has a potential to increase the strength of mortar made of 100% recycled fine aggregate. In case of modified version of two-stage mixing approach which first prepares cement paste and pours recycled fine aggregate into the cement paste, was more effective to increase the strength of mortar made of 100% recycled fine aggregate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.691-702
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• 2021

This study aimed to provide basic data for safety education by surveying the status of safety education and general safety awareness among high school students by gender and school type in Chungnam area. From July 16th to October 15th, 2015, 1214 copies collected from 16 schools were analyzed using SPSS ver 23.0. Regarding safety education, females and general high school students (GHS) responded more frequently that safety education was more necessary for school life compared to males and specialized high school students (SHS), whereas males were more interested in safety education content than females. Males and SHS lost interest when learning unfamiliar content compared to females and GHS, respectively. In terms of general safety awareness, males and GHS usually followed safety rules better than females and SHS, and males demonstrated greater knowledge of first aid. Males and SHS acted according to their beliefs towards safety rather than knowledge compared to females and GHS, respectively. This study found a significant difference in safety education and general safety awareness among high school students by gender and type of school, and the results suggest that differentiated safety education is necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.867-872
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• 2020

Oil storage tanks are a major structure in chemical industrial complexes. Damage to the structure due to natural disasters or poor management can cause additional damage, such as leakage of chemicals, fire, and explosion, so it is essential to understand the deformation. In this study, data on oil storage tanks were acquired using a 3D laser scanner, and various analyzes were performed for storage tank management by comparing them with design data. Modeling of the oil storage tank was performed using the data and design drawings acquired by a 3D laser scanner. An inspection of the oil storage tank was effectively performed by overlapping. In addition, cross-sectional and exploded views of the deformation were produced to generate visible data on the deformation of the facility, and it was suggested that the oil storage tank had a maximum deformation of -7.16mm through quantitative analysis. Data that can be used for additional work was obtained by producing drawings to be precisely inspected for areas with large deformation. In the future, an inspection of oil storage tanks using 3D laser scanners is quantitative and visible data on oil storage tank deformation. This will greatly improve the efficiency of facility management by rebuilding it.

• Journal of the Korea Society of Computer and Information
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• v.26 no.8
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• pp.127-137
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• 2021

This research studies the perception types of 119 rescue workers among emergency rescue department students, and was carried out to identify the types of perception of 119 rescue workers among firefighters and to prepare basic data to find out the characteristics of each type. As a result of analysis on the Q sample consisting of 27 statements by executing the Q UANL program on a total of 54 students from the Emergency rescue department, it is confirmed that there were 3 types, which accounted for 45% of the total variable. When looking at the explanatory power per type, it turned out: 32% for Type I; 6.7% for Type II; and 5.8% for Type III. Each type was named as follows: our Superman for Type I ; suffering hero for Type II ; and rescue expert for Type III. Overall, there were 119 rescue workers as follows : rescue workers in lexical meaning; and 119 rescue workers who were in difficult situations suffering from post-traumatic stress disorder and needed to be covered and protected by citizens. In addition, there was a perception of 119 rescue workers who were recognized as a specialist and carry out his/her lifesaving duties without a single mistake. Therefore, in order for 119 rescue workers to be recognized as a specialized field of rescue, a program in which 119 rescue workers can share various training and experiences must be provided and researched.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.463-473
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• 2020

This study was conducted to provide basic data to find measures to alleviate the job stress of 119 Emergency Medical Technicians by identifying the mediating effect of resilience for life care in the relationship between stress coping and job stress of 119 Emergency Medical Technicians. The data for this study were collected from October 5, 2019, to October 31, 2019. The subject was 205 119 Emergency Medical Technicians working in 119 safety centers located in G Metropolitan City. The collected data were analyzed by independent t-test, ANOVA, Scheffé test, Pearson's correlation coefficients, hierarchical multiple regression analysis, and Sobel test using the SPSS Statistics 21.0 program. As a result oh the study, The mediation effect of resilience was not statistically significant in the relationship between stress coping of seeking social support type and job stress; the mediation effect of resilience was not statistically significant in the relationship between stress coping of seeking positive thinking type and job stress. but, resilience was revealed that resilience completely mediates the relationship between problem-solving type and job stress, and partially mediates the relationship between avoidance type and job stress. The measures to reduce the job stress of 119 Emergency Medical Technicians derived from the above results are as follows. First, among the 119 Emergency Medical Technicians, problem-solving stress coping type 119 Emergency Medical Technicians need to reduce job stress through resilience improvement program. Second, avoidance stress coping type 119 Emergency Medical Technicians should take part in education programs that can reduce job stress in parallel with resilience improvement program.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.1-10
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• 2022

As the volume of marine hazardous and noxious substances (HNSs) transported in domestic and overseas seas increases, the risk of HNS spill accidents is gradually increasing. HNS leaked into the sea causes destruction of marine ecosystems, pollution of the marine environment, and human casualties. Secondary accidents accompanied by fire and explosion are possible. Therefore, various types of HNSs must be rapidly detected, and a control strategy suitable for the characteristics of each substance must be established. In this study, the ground HNS spill experiment process and application result of detection algorithms were presented based on hyperspectral remote sensing. For this, styrene was spilled in an outdoor pool in Brest, France, and simultaneous observation was performed through a hyperspectral sensor. Pure styrene and seawater spectra were extracted by applying principal component analysis (PCA) and the N-Findr method. In addition, pixels in hyperspectral image were classified with styrene and seawater by applying spectral matching techniques such as spectral distance similarity (SDS), spectral correlation similarity (SCS), spectral similarity value (SSV), and spectral angle mapper (SAM). As a result, the SDS and SSV techniques showed good styrene detection results, and the total extent of styrene was estimated to be approximately 1.03 m². The study is expected to play a major role in marine HNS monitoring.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1249-1249
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• 2022

The facade, an exterior material of a building, is one of the crucial factors that determine its morphological identity and its functional levels, such as energy performance, earthquake and fire resistance. However, regardless of the type of exterior materials, huge property and human casualties are continuing due to frequent exterior materials dropout accidents. The quality of the building envelope depends on the detailed design and is closely related to the back frames that support the exterior material. Detailed design means the creation of a shop drawing, which is the stage of developing the basic design to a level where construction is possible by specifying the exact necessary details. However, due to chronic problems in the construction industry, such as reducing working hours and the lack of design personnel, detailed design is not being appropriately implemented. Considering these characteristics, it is necessary to develop the detailed design process of exterior materials and works based on the domain-expert knowledge of the construction industry using artificial intelligence (AI). Therefore, this study aims to establish a detailed design automation algorithm for AI-based condition-responsive exterior wall panels and their back frames. The scope of the study is limited to "detailed design" performed based on the working drawings during the exterior work process and "stone panels" among exterior materials. First, working-level data on stone works is collected to analyze the existing detailed design process. After that, design parameters are derived by analyzing factors that affect the design of the building's exterior wall and back frames, such as structure, floor height, wind load, lift limit, and transportation elements. The relational expression between the derived parameters is derived, and it is algorithmized to implement a rule-based AI design. These algorithms can be applied to detailed designs based on 3D BIM to automatically calculate quantity and unit price. The next goal is to derive the iterative elements that occur in the process and implement a robotic process automation (RPA)-based system to link the entire "Detailed design-Quality calculation-Order process." This study is significant because it expands the design automation research, which has been rather limited to basic and implemented design, to the detailed design area at the beginning of the construction execution and increases the productivity by using AI. In addition, it can help fundamentally improve the working environment of the construction industry through the development of direct and applicable technologies to practice.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.127-143
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• 2023

Currently, the domestic traditional market has not escaped the swamp of stagnation that began in the early 2000s despite various projects promoted by many related players such as the central government and local governments. In order to overcome the crisis faced by the traditional market, various R&Ds have recently been conducted on how to build a smart traditional market that combines information and communication technologies such as big data analysis, artificial intelligence, and the Internet of Things. This study analyzes various previous studies, users of traditional markets, and application cases of ICT technology in foreign traditional markets since 2012 and proposes a model to build a smart traditional market using ICT technology based on the analysis. The model proposed in this study includes building a traditional market metaverse that can interact with visitors, certifying visits to traditional markets through digital signage with NFC technology, improving accuracy of fire detection functions using IoT and AI technology, developing smartphone apps for market launch information and event notification, and an e-commerce system. If a smart traditional market platform is implemented and operated based on the smart traditional market platform model presented in this study, it will not only draw interest in the traditional market to MZ generation and foreigners, but also contribute to revitalizing the traditional market in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.76-85
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• 2023

Demand for hydrogen as a renewable energy resource is increasing. However, unlike conventional fossil fuels, hydrogen requires a dedicated refueling station for fuel supply. A risk assessment of hydrogen refueling stations must be undertaken to secure the infrastructure. Therefore, in this study, a risk assessment for hydrogen refueling stations was conducted through both qualitative and quantitative risk assessments. For the qualitative evaluation, the hydrogen dispenser module was evaluated as two nodes using the hazard and operability (HAZOP) analysis. The risk due to filter clogging and high-pressure accidents was evaluated to be high according to the criticality estimation matrix. For the quantitative risk assessment, the Hydrogen Korea Risk Assessment Module (Hy-KoRAM) was used to indicate the shape of the fire and the range of damage impact, and to evaluate the individual and social risks. The individual risk level was determined of to be as low as reasonably practicable (ALARP). Additional safety measures proposed include placing the hydrogen refueling station about 100m away from public facilities. The social risk level was derived as 1E-04/year, with a frequency of approximately 10 deaths, falling within the ALARP range. As a result of the qualitative and quantitative risk assessments, additional safety measures for the process and a safety improvement plan are proposed through the establishment of a restricted area near the hydrogen refueling station.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.29-39
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• 2023

In the recent period, there have been numerous earthquakes both domestically and internationally, and buildings in South Korea are particularly vulnerable to seismic design and earthquake damage. Therefore, the objective of this study is to discover an effective method for assessing the seismic vulnerability of buildings and conducting a density analysis of high-risk structures. The aim is to model this approach and validate it using data from pilot area(Seoul). To achieve this, two modeling techniques were employed, of which the predictive accuracy of the statistical analysis technique was 87%. Among the machine learning techniques, Random Forest Model exhibited the highest predictive accuracy, and the accuracy of the model on the Test Set was determined to be 97.1%. As a result of the analysis, the district rating revealed that Gwangjin-gu and Songpa-gu were relatively at higher risk, and the density analysis of at-risk buildings predicted that Seocho-gu, Gwanak-gu, and Gangseo-gu were relatively at higher risk. Finally, the result of the statistical analysis technique was predicted as more dangerous than those of the machine learning technique. However, considering that about 18.9% of the buildings in Seoul are designed to withstand the Seismic intensity of 6.5 (MMI), which is the standard for seismic-resistant design in South Korea, the result of the machine learning technique was predicted to be more accurate. The current research is limited in that it only considers buildings without taking into account factors such as population density, police stations, and fire stations. Considering these limitations in future studies would lead to more comprehensive and valuable research.